Month-by-Month Guide to

Caring for Your Irises

Here is the useful iris care checklist developed by avid iris lovers, Leon and Norma Vogel, who have a lovely garden in Murrieta, California with their irises planted among many other flowering plants.

January and February

  • Fertilize again for the Spring burst of blooms.
  • Check for aphids that hid all winter at base of leaves.
  • Discard all dead leaves and weeds.
  • Check to see if all labels are properly set by proper iris clumps.
  • Keep irises watered if a dry winter.
  • Foliar feed for bigger and brighter colored blossoms.

March and April

  • Look for first blooms in mid-March and all through April.
  • Check for aphids and white fly and spray if they are seen.
  • Water regularly if a dry winter.
  • Make last foliar feeding for more flowers.
  • Clean weeds and dead leaves.
  • Give Japanese and Louisiana iris an application of an acid food -- a camellia-type fertilizer is good.

May and June

  • Continue to enjoy lots of blooms into early June.
  • Check to see if all the iris labels match their name (check bloom description)..
  • Cut the bloom stalk near the ground when done blooming.
  • Feed heavily (one tblsp. per rhizome) with 6-20-20 or similar mix when bloom season is over.
  • Check for aphids near the rhizomes, also for leaf rust.
  • Keep weeds and dead leaves removed.
  • Do not neglect to water enough to keep them growing, but be careful not to over-water.

July and August

  • Dig clumps that are over-crowded. Divide and share rhizomes with friends.
  • Dig whole beds if necessary to thin the clumps.
  • Be sure to add amendments to soil such as fertilizer, peat moss, compost, gypsum and new top soil.
  • Rototill the soil well and allow to stand for a week if possible before planting new iris rhizomes.
  • Feed (fertilize) at least 3 times yearly. Foliar feed in between for stellar results. Irises are heavy feeders.
  • Irises can remain out of ground for 3 weeks or more before replanting. Keep dug rhizomes in cool dry place for storage.
  • Replant rhizomes, the top 1/4 should be showing above the soil line to prevent rot and allow them to breathe.
  • Trim the roots back to an inch when replanting-- they send out all new roots within a few weeks.
  • Do not neglect to water enough to keep them growing. New beds require more water.
  • Reblooming irises may surprise you with flowers in July-February.

September and October

  • Complete digging and replanting of your irises.
  • Fertilize again. Irises grow all winter long in Southern California. This differs from colder climates where you would want your irises to go dormant in the winter.
  • Plant any new iris you may have purchased. Label your irises. Be sure mark in water-proof ink.
  • Keep weeds under control. Check for aphids and white fly and spray with insecticidal soap, if necessary.
  • Pull off and discard all dead leaves.

November and December

  • If for some reason you didn’t get all the things done, it is not too late to fertilize or plant new irises.
  • Pull weeds as necessary.
  • Check for aphids often particularly if the winter is mild.
  • Keep the beds clean of everything except growing iris.
  • If you have reblooming iris, they need extra fertilizer and water. You can have iris blooms year-round if you include “reblooming” irises.

Photo of tall bearded iris 'Solar Fire' growing in Jim and Edith Schade garden in Ramona, CA.